smelly when it rains?

[CharlieH]

I am no construction expert, but would welcome thoughts and suggestions on why the loo smells when it rains? I have seen other threads around TVisa, of people commenting on the same thing but no one being able to say why?

I have a bathroom in one part of the house, the waste goes out some 5 meters away from the nearest wall, its deep with those concrete rings etc. It has a top access for emptying, other than that there is concrete on top and stretching a good 20 meteres in any direction. So when it rains heavily I cant see the rain water getting any where near it, so why does it smell when it rains?

[pinkpanther99]

Yes, this happens at my house too! After it rains, the bathroom smells as if someone has only recently used it for a you know what.

[trogers]

Probably because your septic tank is of traditional construction using concrete rings instead of the modern plastic types. The latter has a proper vent outlet that you pipe to roof level.

Edited November 7, 2013 by trogers

[CharlieH]

Probably because your septic tank is of traditional construction using concrete rings instead of the modern plastic types. The latter has a proper vent outlet that you pipe to roof level.

Interesting and informative but doesnt answer the question.

[mad mary]

Probably because your septic tank is of traditional construction using concrete rings instead of the modern plastic types. The latter has a proper vent outlet that you pipe to roof level.

Interesting and informative but doesnt answer the question.

it does ...

[FiftyTwo]

The manhole cover on your septic tank isn't screwed and sealed (as it should be).

The trap isn't installed correctly between toilet and tank.

The grey water drain is not sloping away from the tank.

Rainwater is leaking in and flooding the septic tank.

Take your pick.

Edited November 7, 2013 by FiftyTwo

[allexx]

Your toilet/septic tank has no water trap.

[Utley]

Ground water may be seeping into your septic tank from the bottom. If your tank doesn't have an air vent and/or your toilet doesn't have a "J" trap to stop septic gas from coming into your loo, the heavy rains are probably forcing septic gas back into your home. Installing a J trap and a septic tank air outlet should fix your problem.

[fxe1200]

Your toilet/septic tank has no water trap.

...also called "stink trap". I keep a plastic yoghurt container upside down on the drain and remove it, when I take a shower. That helps.

[impulse]

Are you sure it's not windy days?

With the poor design of the P-Traps, a stiff wind blowing across the vent pipes open to the roof will cause the "vapors" to back up into the house.

That's how I knew it was a windy day in China- long before I looked outside.

[kaptainrob]

Practically all responses are correct subject to your actual inspection. 1st thing required is the PV or permanent vent from as close to toilet waste outlet as possible, to above roof level. This will vent sulfurous gases to atmosphere. 2nd, grey water or shower/vanity wastes need a u-trap somewhere in the line ... easy to install in-ground or at the pit with a few 90 degree elbows.

[lucjoker]

.... so why does it smell when it rains?

You are too nosy !(maby the former owner buried his misses in the septic tank? Lots of reasons !

solution: stay out off your BR when it rains!

or : go have a beer when it rains?Oil-massage?

[Jeffrey346]

Check to see if your septic tank is vented. If not, have it done. While your at it, have the tank pumped and cleaned and install the j-trap. Your problem will go away.

[Richmah]

This happens to the most newly built houses,

because they did not use a pvc u-turn pipe,

that is a one way inside the u-turn pipe.

Even my hse also the same thing, it smells when it rains,

what i do, cover it up with a bowl on top of the hole in the toilet.

The smells stops. All the pipes connected together into the temporary

septic tank, and the gas reverse and goes back to the toilet.

That the answer.

Dont demand too much on thai style constructions,

many shortcuts they use, ok.

[FiftyTwo]

This happens to the most newly built houses,

because they did not use a pvc u-turn pipe,

that is a one way inside the u-turn pipe.

Even my hse also the same thing, it smells when it rains,

what i do, cover it up with a bowl on top of the hole in the toilet.

The smells stops. All the pipes connected together into the temporary

septic tank, and the gas reverse and goes back to the toilet.

That the answer.

Dont demand too much on thai style constructions,

many shortcuts they use, ok.

Some of the replies lead me to think their shower drains are connected to their septic tanks???

Surely not!

[ozyjon]

As a builder i know that any pipe work going to the sewer needs a trap (to stop the smell going baack into the house) also the pipe work needs an air vent to go from the septic up higher than the roof line to take the smell away,, now how many buildings have those simple things in place,, it's simple so have a look to see where the smell is going and if you can put a trap somewhere in between.

[sawadeeken]

Most Thai's just accept the smell and don't stay there long. And many posts are saying that the toilet is the source, but I disagree. Every 'farang' style toilet has a trap built in it so it won't allow gasses to come back into the bathroom. The source of the smell is the shower drain (almost always) plus in many cases the sink if it doesn't have a j-trap (p-trap/air trap) built into the drain.

Also, many sources feed into your septic tank (cement rings) and depending on your house you could have a back porch with a small grill covered drain hole (similar to a shower drain) in the cement floor (or some other source for rain water to enter the septic tank). THEN. when a massive amount of water enters the septic tank, the air (smelly air) has to go somewhere, so it goes in the reverse direction - into your house at places that don't have some kind of 'trap' to prevent it.

Best remedy: add a vent from your septic tank using at least 2 inch plastic pipe to above roof level. then all those gasses you are getting will go out from the septic tank into the atmosphere and not into your bathroom.

I have had to break concrete floors to do it, but I have installed U-traps (J-traps or what ever you like to call them) into my shower drain and installed a p-trap under my sink (the toilet has it's own built in trap). All of those 'traps' work the same- the bottom part of the 'U' holds water and creates a natural block for gasses coming back up the pipes since there is normally very little pressure pushing the gasses.

It is all in 'therory' of how things work:. Basically when you add liquid to a container, the air above the liquid is displaced having to go somewhere (in your case your shower is probably the path of least resistance). SECONDLY: rain water MUST be entering your septic tank from SOMEWHERE. SIMILARLY: in your case the septic vent should create an easier path for the gasses to leave the septic tank once rain water enters.

It may cost you a few bucks, but at Thai wages it won't cause you any major hardship to have somebody come in and make the necessary repairs - or you could do it yourself, I have several times........... Hope this explaination has been helpful............. Ken

[sawadeeken]

This happens to the most newly built houses,

because they did not use a pvc u-turn pipe,

that is a one way inside the u-turn pipe.

Even my hse also the same thing, it smells when it rains,

what i do, cover it up with a bowl on top of the hole in the toilet.

The smells stops. All the pipes connected together into the temporary

septic tank, and the gas reverse and goes back to the toilet.

That the answer.

Dont demand too much on thai style constructions,

many shortcuts they use, ok.

Some of the replies lead me to think their shower drains are connected to their septic tanks???

Surely not!

MOST CERTAINLY THEY ARE CONNECTED TO SEPTIC TANKS - shower drains go the same place as toilet, bathroom sink, kitchen sink, etc. WHERE ELSE? In outdoor showers it may possibly just run off the edge of the cement floor to the dirt outside, But NEVER from a proper indoor bathroom shower...........

[lineofentry]

Fast flow rates in pipework during rain can cause a low presure siphon effect in your water traps, causing the water level to drop below the seal line thus allowing drain gasses into your bathroom. Check the water level in the toilet hasn't dropped too low.

Concrete ring cesspits leach a certain amount of liquid into the surrounding ground where it is absorbed and broken down naturally by the soils, in heavy rain the ground becomes waterlogged and this could bring smelly effluent liquids to the surface.

[jacko45k]

Rainwater getting into the septic tank creating back-bubbling.

Check all your water traps.

Toilets themselves should have an effective trap, but floor outlets and sinks can have no water or dry out.

In Thailand they often don't install vents to prevent back-pressure or vacuum (which pull water from the traps).

Even a little vent fan in the bathroom can create a small gas pull.

The floor outlets have an inverted plastic cup to create a trap, take a good look at them, clean them out.

I found 3 where no cups were fitted.

One sink did not have a U-bend or water trap.

Also check the levels in septic/ gray water seep aways.

[jaapfries]

This happens to the most newly built houses,

because they did not use a pvc u-turn pipe,

that is a one way inside the u-turn pipe.

Even my hse also the same thing, it smells when it rains,

what i do, cover it up with a bowl on top of the hole in the toilet.

The smells stops. All the pipes connected together into the temporary

septic tank, and the gas reverse and goes back to the toilet.

That the answer.

Dont demand too much on thai style constructions,

many shortcuts they use, ok.

Some of the replies lead me to think their shower drains are connected to their septic tanks???

Surely not!

Surely: YES ! ! In Thailand, many builders adopt the practice of connecting Shower, Kitchen & Sink (Vanity) outlets to the Septic-Tank, because it is cheaper for them (only 1 connection to make !). This is obviously not only very wrong, but also very dumb. A Septic-Tank works on the principle of "Waste Break-Down by means of Bacterial Action". The very LAST thing you want to introduce to this 'natural' and very effective process is Soap-Residue, Detergents etc., since these products will kill the bacteria and hence stop the process of "breaking-down" the waste effectively.

The ONLY matter which is supposed to go into a Septic Tank is the 'product of the Toilets'; nothing else.

Shower, Kitchen & Sink (Vanity) outlets are supposed to be connected to the storm-drain (this is the connection which also takes rain-water etc.,).

"Jelly-Fish" Solution:

If your shower drain gets smelly, just 1/2 fill a small plastic bag with water, tie it up tightly and lay this "jelly-fish" on top of the drain. Warning: only do this while you are at home, because if you go out and there's a waterline break, your house may get flooded. So; when you go out; take the "Jelly-Fish" away.

[F4UCorsair]

Practically all responses are correct subject to your actual inspection. 1st thing required is the PV or permanent vent from as close to toilet waste outlet as possible, to above roof level. This will vent sulfurous gases to atmosphere. 2nd, grey water or shower/vanity wastes need a u-trap somewhere in the line ... easy to install in-ground or at the pit with a few 90 degree elbows.

Rob's on the money!! That is the solution.

[Billmont]

We had same problem, smell coming back up the floor drain in guests bathroom. Builder returned and added a 1 inch air vent from underground receptacle to our garden wall and the upright is only less than 1 metre high with a "T" top to prevent rain entering. Problem solved for us. Over two years now and no smell. Builder said sorry, air vent should have been fitted originally but over looked.

[Mrjlh]

Might make sure you have a "u-trap" on the sinks too. Gas will come up and out the drain. Too often they are connected to the septic system.